Retractable landing gear used on an aircraft require an indicator to show the pilot that the gear are up or down, as the landing gear is normally out of view of the pilot sitting in the cockpit. It is very dangerous to land if one or more gear legs are partially extended, as collapse would almost certainly result. Conversely, if one or more gear were not fully retracted, drag and fuel consumption would be excessive and the aircraft structure could be overly stressed at high speed. Indicator systems currently in use have at most one light per landing gear which illuminates when the gear is fully down, and a warning light to show when there is a problem. Gear retraction is deduced by the position of the landing gear switch and by the extinguished indicator lights.
Accordingly, it is an object of the invention to provide additional gear status information.
A further object of the invention is to provide an indicator system which displays in transit (extension or retraction) information.
Another important object of the invention is to provide an indicator system which displays an indication that the gear have completed their travel to the required limits.